After Eartha, we thought we were done with designing community composters. However, we hit a roadblock as transporting a few units of Eartha to places like New Delhi, Mumbai or even Pune, meant attracting a massive shipping fee which many interested buyers found inhibiting.
That’s when we began working on an assembly model which we had only discussed briefly before. However, we soon realised that translating user-friendly ideas into an FRP product was far from simple. Ultimately, the material used has a lot of influence on the design itself. So no wonder EIRA took more than 1.5 years to materialise, beaten into a shape and size that’s absolutely easy to work with and bring out loads of compost. All the credit goes to my colleague Prasanna Kumar for staying fixated on this idea and the never-say-die engineering team that kept going back to the drawing board repeatedly till every minute detail was worked out to their satisfaction.
Between January-June 2022, the three trials conducted right under my nose using my apartment’s kitchen waste saw a flourishing finish with three heaps of fine-quality compost sieved and cured to perfection. The first trial was conducted indoors where aeration / cross-ventilation was abundant and processed with only cocopeat as bulking material. The second trial was conducted outdoors using dry leaves (and no cocopeat whatsoever), and the third one was also held outdoors but with only cocopeat and no dry leaves.
EIRA (ih-RAH) means Goddess Saraswati or ‘the earth’ in Sanskrit. Needs no elaboration, I guess.
Made of fibre-reinforced polymer (FRP), Eira aerobic composter has 1200 litres of capacity with 3.5 ft L x 3.5 ft W x 4 ft H dimensions. We had plans of using 30% of stainless steel but backed out because even SS can catch rust after a prolonged exposure to heat and moisture. So the final version is 100% FRP barring the single aerator PVC pipe placed right in the centre. All the accessories—nuts, bolts, hinges, prop hood and tie rod—are made of stainless steel and can be easily sourced locally.
Assembly model: This is the most striking feature of this composter. We as a team have always felt the need to have an easy-to-assemble piece which can be shipped all over India. Eira gets delivered to you in a flat pack with nine components. Its two side walls and the rear wall have a single panel whereas the front wall has three panels which can be dislodged easily to carry out the work. Please refer to the YouTube video and the instruction manual to assemble the unit.
Worker-friendly design: The workers can work their way up from the bottom-most front panel instead of bending forward from its full height. While starting a batch, spread the filter fabric as shown in the video, fix the aerator, place only the bottom-most front panel and start adding layers of inputs as suggested in ‘The Process’ below. Once the contents reach the height of the bottom-most panel, fix the middle panel and work your way up. Finally, place the topmost panel, fill the contents till EIRA is almost full and then let it do its job.
Compost tea strainer: Similar to Eartha, Eira also has a compost tea strainer or separator which sits a few inches above the base. This plate has holes which let excess moisture seep down. The same can be collected from the tap fixed on the right side of the composter. Make sure collection happens regularly. Do not let it stagnate as it can trigger odour issues.
Filter fabric: This is a newly added accessory. The fabric is porous and lasts years. Since it lets only clear liquid drip down, extraction of compost tea through the tap is a lot easier as even the finest cocopeat/compost particles fail to hit the base plate.
The stand: Made of MS, this sturdy stand comes powder-coated. It takes away the pain of getting a platform constructed to place the composter. The height of the stand allows you to extract the compost tea with ease.
The base: Enough attention-to-detail has gone into ensuring that the liquid flows towards the tap without getting stagnated here and there.
The prop hood: Use this SS rod to keep the lid open while working. Do not let the lid fall backward as it can damage the SS hinges.
The tie rod: This keeps the side panels in place and can be easily taken out and placed back as needed.
The aerator: Since all the walls have ample aeration vents, only one aerator has been placed in the centre. (Please note: the prototype used for all the trials had no aerator as was originally designed).
FRP body: Fibre-reinforced polymer (FRP) means durability. It’s the same material used for making boats and aeroplanes. It is light-weight, all weather-resistant and rust-proof. Combined with SS, it’s the perfect material that can withstand moisture and temperature day in and day out. It is painted with automobile paints.
Once you assemble Eira, spread the filter fabric over the compost tea separator and fix the aerator as shown in this video. Put a thick layer of Endlessly Green cocopeat at the bottom. You can also use dry leaves if you prefer. Spread a layer of shredded kitchen waste and a layer of cocopeat on top of it. Repeat the process till you reach the top leaving the tip of the aerator free so that airflow goes on unhindered. Always cover the top layer with cocopeat or dry leaves to prevent fruit flies from accessing the food waste. Follow the process till the last composter is filled up. By then, the first one will be ready for harvesting.
If you find the layering process time-consuming, then go for the mixing method (as shown in the video). After the bottom layer of cocopeat or dry leaves is prepared, then get the shredded waste and microbial cocopeat mixed in suggested proportions and transfer it to the composter. Just put a layer of cocopeat on top of it.
Suggested kitchen waste-cocopeat ratio: Mix three measures of shredded kitchen waste with one measure of cocopeat. Spread it evenly. Put one more measure of cocopeat on top of this layer. Follow the same procedure till the composter is filled up. To cut costs, you can also use dry leaves for layering in between. But dry leaves consume a lot of space.
HARVESTING & SIEVING
Harvesting compost from an enclosed unit can’t get easier than this. Just dislodge all the front three panels and go digging in. Once all the compost is taken out, remove the aerator. Take out the filter fabric and rinse it well in plain water. It’s now ready for reuse!
For sieving, use a locally fabricated mesh sieve (as shown in the video) and sieve the compost. The fine compost can be put aside for curing and the coarse portion can be used for the next batch or as a mulching agent for full-grown trees or bushes.
What happened so far is the first stage of composting. The second stage is curing. You can use any aerated container for this purpose. Make sure the compost is moist before and even after curing. Keep it moderately aerated till the pile cools down completely. It usually takes about 3-4 weeks to cure if the compost is sieved. We recommend fertiliser bags for curing. Just fill the bags to half their capacity and leave the mouth open. Curing happens without any hassle.
- Method: Aerobic.
- Capacity: 1200 litres. Up to 30 kg per day for 30 days, or 850-900 kg at once when the waste is shredded/chopped and only cocopeat is used as bulking material.
- Add-on supplies: Endlessly Green cocopeat & Excelerator Compost Culture.
- Infrastructure: 3.5ft L x 3.5ft W x 4ft H.
- Processing time: 4+ weeks. Processing speed depends on the particle size, the accelerator used and the ambient temperature. During our trials, one cycle took about four weeks when cocopeat was used and more than two months when only dry leaves were used.
- Capital expenditure: A one-time investment of Rs 3,000-3,500 per household (for a 100-home community) which holds good for at least 15 years if the composters are maintained well.
Operational expenditure: About Rs 50 / batch / home (for a 100-home community).
- Features: Sturdy FRP body, durable and low maintenance. No frequent repainting.
- Outdoor installation preferred.
- Shredder is a must for large quantities.
ENDLESSLY GREEN SHREDDER/CHOPPER
Endlessly Green shredder is an efficient machine with double shaft stainless steel blades. It is almost noiseless and pretty compact. For more details, click here.
ENDLESSLY GREEN COCOPEAT
This is available in both block and powder form. It is also priced quite reasonably which allows you to keep your operational expenditure low. Our microbial cocopeat is very well-processed, has the right degree of electrical conductivity and is well-decomposed. Even the powdered version contains just the right amount of moisture so that the microbes survive but still has enough capacity to absorb extra moisture from the food waste. To know more about the difference between microbial cocopeat bricks/blocks and powdered cocopeat, quality standards and processing methods, click here. Any order of 500 kg and above is shipped free of cost.